A proposed mechanism for solid bed encapsulation: Based on comparing three dimensional andone‐dimensionalscrew melting models

Abstract

This paper describes how the initial melt generation physics with differing pressure generation dynamics lead to either conventional melting or one dimensional (1D) melting. An historic review of the development of single screw melting models is presented. First, a review of the classic model is briefly presented. Second, after an analysis of literature melting data developed using the Maddock solidification procedure, a screw rotation concept melting model is presented that correlates very well with the melting analysis. Third, a new 1D film melting model is developed to analyze melting when the melt film does not encapsulate the solid bed. This physical model provides for the first time a quantitative model for the initiation and ultimate solid bed melting of the 1D melting process. Finally, a new concept and resulting model demonstrate that Reynold's barring concept for pressure generation in the initial melt film at the barrel interface may provide the mechanism that relates to whether the solid bed is or is not encapsulated.